[MetaSounds][Audio Bus] - MetaSound Sources using Audio Bus nodes spam underruns when Audio Mixer Sample Rate is less or greater than 48kHz

UE - Audio - Audio Bus - Oct 5, 2023

Setting the Audio Mixer Sample Rate to 32000kHz causes underrun spam in audio bus reader and writer nodes and sounds to playback jittery. Tested with 24kHz and 32kHz. Does not repro in //Fortnite/R ...

Calling UBlueprintMapLibrary::GenericMap_Find with a non-existent key causes a memory leak

UE - Framework - Blueprint - Apr 15, 2025

When Calling UBlueprintMapLibrary::GenericMap_Find with a non-existent key, the function construct the default structure in-place on the given pointer without destroying the object. This behavior ca ...

Duplicated TextureLoadVirtualPageTable in GetCustomData functions in generated HLSL add to the total instruction count due to TextureLoad having side effects

UE - Rendering Architecture - Materials - Dec 4, 2024

When using materials with CustomData inputs, such as the Eye material with Iris Distance and Mask, Virtual Texture samples will increase the instruction count for each unique VTPageResult. Each cus ...

Excessive RVT page updates with Nanite and ClearCoat or Cloth shading model applied

UE - Rendering Architecture - Mar 31, 2025

There is an excessive number of page updates when a Nanite landscape has a runtime virtual texture material applied to it with a shading model set to ClearCoat or Cloth (instead of Default Lit). The ...

FCableSceneProxy::BuildCableMesh thrashes memory allocator

UE - Simulation - Physics - Feb 12, 2025

FCableSceneProxy::BuildCableMesh in CableComponent.cpp:233 showed up as a hot spot in profiling because the two TArray allocators in SetDynamicData_RenderThread used by BuildCableMesh are created an ...

OFPA Localizable Text Instances are not gathered when world partitioning is disabled

UE - World Creation - Worldbuilding Tools - OFPA - Mar 7, 2025

Context One File Per Actor (OFPA) reduces overlap between users by saving data for instances of Actors in external files, removing the need to save the main Level file when making changes to its Act ...

Inaccurate motion vectors when using different position binding in renderer

UE - Niagara - Rendering - Jul 27, 2023

Even though the particles are not moving, and the velocity is zero, the output motion vectors are non-zero. This seems to only happen if using two sources of particle positions.  ...

Horde server fails to build Docker image

UE - Foundation - Horde - Server - Apr 1, 2025

If you attempt to build the Horde server Docker image right now it fails unless you have some of the layers cached or a nuget proxy/cache that has cached some packages. JetBrains have renamed their ...